Cold Mass Support System for the MSU Superconducting Cyclotron Gas-Stopper Magnet

Abstract

The cyclotron gas-stopper magnet at Michigan State University consists of two superconducting coils, each in its own cryostat. The two cryostats are mounted in the two warm iron poles of a sector cyclotron magnet used to control the orbit of heavy ions as the particle energy is being removed by circulating the ions through helium gas. Because the two poles of the magnet must be separated to install the gas chamber and beam extraction system, the magnet coils cannot be connected together. As a result, the magnet cold mass support system must carry the forces pushing the magnet into the iron pole as well as any decentering forces that occur from coil placement errors. The cold mass support system for each magnet coil consists of six compression supports that support magnet forces in the axial direction. In addition, there are three radial supports to center the coil axis coaxial with the axis of the iron poles. This paper presents an analysis of the superconducting magnet cold mass support system, which must be designed to have a spring constant that is higher than the magnet force constant at the full design current for the magnet.